1. Technical Field
The present disclosure relates to the field of noise control in audio signals. In particular, to a system and method for mitigating microphone hiss.
2. Related Art
There are many types of microphones each designed for different applications. Microphones may be selected for an application based on factors including cost, size and the dynamic range over a specified frequency range. For example, a microphone utilized in a professional recording application may have a large dynamic range close to the range of human perception from 0 Hz to 16 kHz. The microphone utilized in a mobile phone may have an acceptable dynamic range for speech content from 0 Hz to 5 kHz. The microphones utilized in the mobile phone may be selected for cost reasons but often the dynamic range over a give frequency range may be limited because of the physical size of the microphone.
Mobile phones, and many other computing devices, utilize small microphones because of the small physical size of the computing devices. Physically small microphones may have limitations in the dynamic range over a given frequency range. The limited dynamic range may be audible even in the presence of a completely silent environment. The limited dynamic range of a small microphone at higher frequencies will be perceived as hiss noise.